Pulse compression for airborne weather radar has several advantages. Among these is the ability to provide excellent radar detection performance using a low power transmitter, which allows much lower system cost. Although pulse compression is powerful, it has an inherent drawback because it requires longer pulses to achieve the equivalent peak power signal to noise ratio (SNR) of a system not using pulse compression. This can lead to severe partial pulse interference at close ranges. Partial pulse interference is caused by radar returns from ranges closer than a pulse length from the radar. The radar receiver is turned on after the pulse transmission, so close in returns do not contain complete pulse histories. When partial pulses are processed by the pulse compression portion of the receiver, it results in range side-lobes that can overwhelm data from valid ranges which are greater than the pulse length. The amount of interference is highly dependent on the environment of a particular application. For airborne weather radar, partial pulse interference can cause false detections.
There is therefore a need for a technique to avoid partial pulse interference while maintaining pulse energy and an acceptable signal to noise ratio.